n = int(input("请输入一个正整数"))
i = 0
while i < n:
    j = 0
    while j <= i:
        print("*", end=" ")
        j += 1
    print()
    i += 1
if i == n:
    while i > 0:
        j = 0
        while j <= i-2:
            print("*", end=" ")
            j += 1
        print()
        i -= 1